<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box {
            width: 200px;
            height: 200px;
            margin: 100px auto;
            background-color: lightblue;
            position: relative;
        }
        .box-button {
            width: 50px;
            height: 50px;
            background-color: #ddd;
            position: absolute;
            top: -25px;
            right: -25px;
            border-radius: 50%;
        }
    </style>
</head>
<body>
    <div class="box">
        <div class="box-button"></div>
    </div>
</body>
</html>
